This invention relates generally to filament type vegetation cutters and relates more particularly to improved automatic deployment cutter heads for same.
The present invention relates to improvements upon the vegetation filament cutter head disclosed in U.S. Pat. No. 4,020,553 issued May 3, 1977 to Cynthia Ann Pittinger for Filament Vegetation Trimmer with Basket Woven Automatic Feed Means and Method. The vegetation cutter head disclosed in the aforesaid patent will be referred to as a "basket" cutter head because it comprises a circular base having a plurality of upstanding members circumferentially spaced on the base, and a filament which is wound outside some of the upstanding members and inside others somewhat in the manner of a basket weave. A cover plate is mounted over top of the upstanding members and both the cover plate and the circular base have central holes therethrough for mounting upon the reduced end of a power driven shaft. The entire basket assembly is retained on the end of a drive shaft by a nut. In use, an outer end portion of the filament swings outwardly from one of the upstanding members as the basket is rotated and cuts grass and other vegetation which it encounters. Selected ones of the upstanding members have the filament bearing upon an inside edge thereof. The points of the filament where the filament engages the inside edge of the selected upstanding members are break points where the filament will break after considerable wear. Successive end portions of the filament break off at successive break points and a new end portion is automatically deployed outwardly to continue the cutting operation as the basket head is rotated. The automatic deployment of successive cutting portions of the filament wound upon the basket cage was an important advance in the art of filament trimmers obtained by the invention set forth in U.S. Pat. No. 4,020,553.
Since the filament which is loaded onto the basket style cutter head disclosed in U.S. Pat. No. 4,020,553, is woven onto the post-like members of the circular base, the loading of the basket style cutter head is usually performed by hand. Depending upon the size of the circular base the spacing between upstanding members on the base and the number of turns of filament woven onto the upstanding post-like members, the effort required for hand loading the basket style cutter head will vary and can involve considerable time expenditure.